Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

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Amount of cost not yet recognized for nonvested award under share-based payment arrangement.

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Weighted-average period over which cost not yet recognized is expected to be recognized for award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition.

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Description of service or performance condition required to be met for earning right to award under share-based payment arrangement. Includes, but is not limited to, combination of market, performance or service condition.

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The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

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Stock-Based Compensation - Additional Information (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for grant	2,498,370		2,498,370
Shares granted			2,022,198
Shares granted, weighted average grant date fair value			$ 10.44
Unrecognized compensation cost relating to unvested restricted stock	$ 71,600		$ 71,600
Unrecognized compensation cost relating to unvested restricted stock, recognition period (in years)			2 years 10 months 24 days
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted, vesting period			5 years
Compensation and benefits expense	7,700,000	$ 9,400,000	$ 23,200,000	$ 28,100,000
Performance Based Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted			418,674
Compensation and benefits expense	$ 411,000		$ 689,000
Vesting rights, description			The PSUs have a performance period of January 1, 2019 to December 31, 2021 and vest on April 1, 2022, subject to adjustment or forfeiture, based upon the achievement by the Company of certain performance standards.
Stock Incentive Plan Twenty Twelve \| Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted	81,400		2,022,198
Shares granted, weighted average grant date fair value	$ 10.78		$ 10.44